#!/bin/sh

# NOTE: Must be run as root, so you probably need to setup sudo for this.

# Vars {{{
debug="0"

## Colors {{{
c_redb='\033[1;31m'
c_magentab='\033[1;35m'
c_reset='\033[0m'
## }}}
# }}}

# Functions
## Test if a disk really support SMART {{{
## Smartctl can give an health status even without a full support
## of SMART for some type (eg. scsi or megaraid).
## Exemple : SMART support is: Unavailable - device lacks SMART capability.
is_disk_support_smart() {
	_disk="${1}"
	_type="${2}"

	_smarctl_support_result="/tmp/dsupport.$(basename "${_disk}")"

	smart_support_msg=""

	[ "${debug}" -eq "0" ] && printf "${c_magentab}%-6b${c_reset}\n" "DEBUG : is_disk_support_smart func − check if SMART is supported on : ${_disk}."

	## Create or empty previous file
	true > "${_smarctl_support_result}"

	## Grep only "support" lines from disk's informations
	smartctl -d "${_type}" -i -- "${_disk}" | grep -E "^SMART support is:" -- >> "${_smarctl_support_result}"

	## If the file is not empty
	if test -s "${_smarctl_support_result}"; then
		## Parse all "support" lines
		while IFS= read -r _LINE; do
			if ! printf -- '%s' "${_LINE}" | grep -q -E -- "(Enabled|Available)"
			then
				smart_support_msg="${_LINE}"
			fi
		done < "${_smarctl_support_result}"
	else
		smart_support_msg="smartctl was not able to open ${_disk} DEVICE with ${_type} TYPE."
	fi

	if [ -z "${smart_support_msg}" ]; then
		[ "${debug}" -eq "0" ] && printf "${c_magentab}%-6b${c_reset}\n" "DEBUG : is_disk_support_smart func − SMART seems fully supported on : ${_disk} with ${_type} type."
	else
		[ "${debug}" -eq "0" ] && printf "${c_magentab}%-6b${c_reset}\n" "DEBUG : is_disk_support_smart func − SMART is not fully supported on : ${_disk} with ${_type} type. See smartctl informations :\n${smart_support_msg}"
	fi

	rm -f -- "${_smarctl_support_result}"
}
## }}}
## Test the type of disk with smartctl {{{
## Cause the scanned one might not be the one to use
choose_correct_type() {
	_disk="${1}"
	_scanned_type="${2}"
	_default_type="auto"

	TYPE=""
	SMART_SUPPORT_MSG=""

	for test_type in "${_default_type}" "${_scanned_type}"; do
		is_disk_support_smart "${_disk}" "${test_type}"

		## If no message, the type is correct
		if [ -z "${smart_support_msg}" ]; then
			TYPE="${test_type}"
			SMART_SUPPORT_MSG=""
			return
		else
			SMART_SUPPORT_MSG="${smart_support_msg}"
		fi

	done

}
## }}}

# Create or empty previous files
true > /tmp/dres
true > /tmp/dcheck
true > /tmp/dscan

# Get the list of all available devices
smartctl --scan >> /tmp/dscan

# If the file is not empty
if test -s /tmp/dscan; then
	while IFS= read -r LINE; do
		## Get device path
		DISK=$(echo "${LINE}" | cut -d" " -f1)
		## Try to determine the best type
		SCANNED_TYPE=$(echo "${LINE}" | cut -d" " -f3)
		choose_correct_type "${DISK}" "${SCANNED_TYPE}"

		## If no correct type was found for this device
		if [ -z "${TYPE}" ]; then
			[ "${debug}" -eq "0" ] && printf "${c_magentab}%-6b${c_reset}\n" "DEBUG : SMART is not fully supported."
			DRES=$(printf '%s' "SMART Health Status can't be determine because of:\n${SMART_SUPPORT_MSG}")
			DCODE="2"
			TYPE="unsupported"
			### Still try to display informations about unsupported device (eg. RAID controller,…)
			DID="unsupported-${DISK}"
			DINFO=$(smartctl -i -d "${SCANNED_TYPE}" "${DISK}" | grep -v -E "^smartctl|^Copyright|^$" || printf '%s' "Can't get informations due to no SMART support.")
		else
			[ "${debug}" -eq "0" ] && printf "${c_magentab}%-6b${c_reset}\n" "DEBUG : SMART seems fully supported, proceed normally."
			### Get SMART Health Status and return code
			DRES=$(/usr/sbin/smartctl -H -d "${TYPE}" -n standby "${DISK}")
			DCODE=$?
			### Get disk's serial number and informations
			DID=$(smartctl -i -d "${TYPE}" "${DISK}" | awk '/.erial .umber:/ { print $NF }')
			DINFO=$(smartctl -i -d "${TYPE}" "${DISK}" | grep -v -E "^smartctl|^Copyright|^$")
			### Check if the disk is known from smartmontools database
			DDRIVEDB=$(smartctl -d "${TYPE}" -P show "${DISK}")
		fi

		## Test health status
		DSTBY=$(( DCODE & 2 ))
		DFAIL=$(( DCODE & 8 ))
		DWARN=$(( DCODE & 32 ))

		## According to health, give a weight to each color to easily get the page status
		if test $DSTBY -ne 0
		then
			COLOR="4&clear"
		elif test $DFAIL -ne 0
		then
			COLOR="1&red"
		elif test $DWARN -ne 0
		then
			COLOR="2&yellow"
		else
			COLOR="3&green"
		fi

		## If the model of the disk is known from smartmontools database
		if "${DDRIVEDB}" | grep -qi -- "drive found in"; then
			DDRIVEDB_MSG="&green Device is known in smartmontools database. You might consider using a more advanced plugin such as:
			https://github.com/skazi0/xymon-plugins/blob/master/client/ext/smart"
		else
			DDRIVEDB_MSG="&clear Device is unknown or not complete in smartmontools database. Please take a look to the FAQ:
https://www.smartmontools.org/wiki/FAQ#SmartmontoolsDatabase"
		fi

		## Avoid duplicate device
		if ! grep -q "${DID}" /tmp/dres; then
			## For summary
			echo "${COLOR} $DISK ${TYPE}"

			## For detailed informations
			{
				echo "${COLOR} $DISK ${TYPE}" | cut -c2-
				echo ""
				echo "$DRES" | grep -v -E "^smartctl|^Copyright|^$|^==="
				echo "${DDRIVEDB_MSG}"
				echo "${DINFO}"
				echo "------------------------------------------------------------"
				echo ""
				echo ""
			} >> /tmp/dres
	fi
	done < /tmp/dscan >> /tmp/dcheck

# If the file is empty
else
	echo "1&red Error while scanning devices with smartctl" >> /tmp/dcheck
fi

# Set the global color according to the highest alert
COLOR=$(< /tmp/dcheck awk '{print $1}' | sort | uniq | head -1 | cut -c3-)

# Send informations to Xymon server
$XYMON "${XYMSRV}" "status ${MACHINE}.smart ${COLOR} SMART health check

$(< /tmp/dcheck cut -c2-)

==================== Detailed status ====================

$(cat /tmp/dres)
"

# Clean temp files
rm -f -- /tmp/dres /tmp/dcheck /tmp/dscan

exit 0